Several gastrointestinal disorders, including diarrhea, can be caused by an imbalance in the normal gut flora, usually an increase in harmful bacteria, including pathogenic and putrefactive bacteria such as Clostridium and Bacteroideceae, and/or a decrease in beneficial, acid-forming bacteria such as bifidobacteria.
Antibiotics have been used to treat diarrhea. A major drawback of using antibiotics is that they can be non-selective, killing both the harmful bacteria and the beneficial bacteria.
Diarrhea is also treated with drugs such as Loperamide HCl, commonly sold under the name Immodium.TM., and codeine, that act on the smooth muscle in the walls of the gastrointestinal tract to inhibit peristalsis, the rhythmic waves of muscular contraction that move the contents of the GI tubes. These drugs are effective to treat the symptoms of diarrhea, which typically include increased force and rate of peristalsis. A major limitation, however, is that the cause of the diarrhea is not treated.
Another approach to treating gastrointestinal disorders involves coating the gastrointestinal tract with a composition containing bismuth salicylate, for example, Pepto-Bismol.TM.. The limitation with this method of treatment is that bismuth salicylate is not always very effective at treating the symptoms of diarrhea, and does not treat the cause of diarrhea. Gastrointestinal disorders have also been treated with dietary fiber. Dietary fiber is a general term covering a number of substances, including cellulose, hemicellulose, oligosaccharides, pectins, gums, waxes, and lignin. A more general definition is "endogenous components of plant materials in the diet that are resistant to digestion by human (intestinal) enzymes, i.e., mainly non-starch polysaccharides and lignin." Grant-Thompson., W., "The Fibre Story," in Gut Reactions, Understanding Symptoms in the Digestive Tract, Plenum Press, N.Y., pp. 59 (1989). Dietary fiber can be either soluble or insoluble.
Dietary fiber resists hydrolysis by human alimentary enzymes, but can be fermented by colonic microflora. In general, soluble fiber is more readily fermented than insoluble fiber. The main physiological effects of these substances are on gastric emptying and colonic transit time, and can result in improved glucose tolerance and decreased starch digestion. The fermentation of dietary fiber results in increased bacterial biomass, increased fecal mass, lowering of intracolonic pH due to production of short chain fatty acids, and production of various gases as metabolic end products. One limitation of using dietary fiber is that it can decrease the absorption of vitamins in certain individuals.
Another limitation to using dietary fiber, generally, is that certain dietary fibers are fermented by both harmful and beneficial bacteria. For example, lactulose is used clinically to enrich intestinal sugar sources, since lactulose is not digested or absorbed in human intestines, and reaches the ileum intact. While lactulose is digested by bifidobacteria, it is also digested by other intestinal bacteria, such as Escherichia Coli, and sometimes causes diarrhea. Yawaza, K., and Tamura, Z., Bifidobacteria Microflora, 1(1):39-44 (1982). Other examples of dietary fiber that is digested by both beneficial and harmful bacteria are described in Yamada, H., et al., Cereal Foods World, 38(7):490-492, 491 (1993).
Some dietary fibers are selectively fermented by bifidobacteria, a beneficial bacteria that produces acetic and lactic acid from sugar. An example of this type of dietary fiber is wheat bran hemicellulose, which is composed mainly of arabinoxylans. Yamada, H., et al., Cereal Foods World, 38(7):490-492 (1993). Wheat bran hemicellulose apparently also suppresses the proliferation of harmful bacteria, such as Escherichia Coli. The acid produced by the bifidobacteria suppresses the adsorption of ammonia and amines produced by putrefactive bacteria such as Clostridium.
Inulin and fructose oligosaccharides have been shown to have bifidogenic factors, but it is unclear why these oligosaccharides are primarily fermented by bifidobacteria. Roberfroid, M., Critical Reviews in Food Science and Nutrition, 33(2);103-148 (1993). Transglycosylated disaccharides have also been shown to increase the amount of fecal bifidobacteria and lactobacilli, and decrease the amount of Bacteroidacea and Candida spp. in the feces. Ito, M., et al., J. Nutr. Sci. Vitaminol., 39:279-288 (1993).
Certain compounds can be useful to treat gastrointestinal disorders because they selectively eliminate harmful bacteria. Some polyphenols have been reported to be useful for this purpose. Certain plants containing polyphenols have been used to treat gastrointestinal disorders. Baldi, A., et al., Planta Medica, 58, Supplemental Issue 1, pp. A691 (1992).
Polyphenols (especially flavonoids, for example, compounds with a phenyl-C.sub.3 -phenyl structure, wherein the phenyl rings are functionalized with one or more hydroxy groups) derived from green tea have been reported to significantly decrease the amount of Clostridium perfrigens and other Clostridium spp. (putrefactive bacteria), and significantly increase the amount of Bifidobacterium spp. (acid forming bacteria) in human feces. Okubo, T., et al., Biosci. Biotech. Biochem., 56(4):588-591 (1992).
It is therefore an object of the present invention to provide compositions and methods for treating gastrointestinal disorders in humans and animals.
It is a further object of the present invention to provide an inexpensive feed additive that aids digestion and/or prevents gastrointestinal disorders.
It is yet a further object of the present invention to provide a method for preparing a feed additive composition containing arabinogalactan and polyphenols.